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The pineapple plant (Ananas comosus) is a terrestrial bromeliad that grows in tropical climates worldwide. This sun worshiper thrives only in U.S. Department of Agriculture hardiness zones 10 through 12 in North America and sulks when temperatures dare to drop below 60 degrees Fahrenheit. While it’s a relatively easy plant to grow, the pineapple plant’s leaves may turn yellow due to improper watering, disease or insect infestation.

Excessive Water

The easiest way to kill your pineapple plant is by overwatering. Too much water causes yellowing leaves and potentially lethal root rot. Specialized structures in this plant’s leaves store water for use during periods of drought conditions. The pineapple plant needs watering once about every six to seven days in the absence of rainfall throughout the growing season. It requires water every 10 to 12 days during the winter months. Water just enough to evenly moisten the soil surface and allow it to become dry to the touch before watering again.

Preventable Crookneck

Pineapple plant leaves curl, twist, become brittle and turn a light yellowish-green from a condition known as crookneck. Affected plants may even bend over and grow nearly horizontally. Caused by zinc deficiency, crookneck is easy to treat with 1 percent zinc foliar spray. Dilute one part 6 percent liquid zinc concentrate with 16 parts water. Spray all surfaces of the pineapple plant liberally to the point of runoff. This micronutrient works best with regular use before symptoms of deficiency become noticeable. To provide all the zinc your plant needs to avoid a deficiency, space three applications out evenly over the growing season.

Mealybugs and Wilt

Large colonies of mealybugs feeding on the plant during a short period of time can cause “quick wilt” in pineapples. The condition robs foliage of rigidity and discolors the leaves, changing them from green to yellow or red. Leaf tips may brown and outer leaves become droopy. Mealybugs are relatively easy to kill with a homemade 2 percent insecticidal soap solution. Combine 2 tablespoons of non-degreasing dishwashing soap with 1 quart of water. Apply the solution to all surfaces of the pineapple plant’s foliage to the point of runoff. The best time to use pesticides is early in the morning or late in the afternoon on a calm day when temperatures are below 90 F. Insecticidal soap must cover the pest to kill it, and the material has no residual action after it’s dry. To avoid the possibility of injury to your plant, rinse all the soap off of it about two hours after treatment. You can safely repeat the application every four to seven days throughout the growing season. For the most effective mealybug management, limit ant populations in the immediate area.

Managing Ants

Controlling ants around your pineapple plant is crucial to mealybug management. Because mealybugs supply ants with honeydew, the ants “farm” them, move them from one feeding location to another and protect them from natural predators. Unfortunately, ants are difficult to control organically. You can create a barrier around the perimeter of the garden with a granular hydramethylnon-based bait labeled for multiple ant species. Broadcast 4 ounces of the product over 180 feet in a 12-inch-wide band in early spring. Because condensation neutralizes the granules, don’t apply the material in rainy weather. For best results, repeat the ant treatment at three-month intervals throughout the growing season.

About the Author

A full-time writer since 2007, Axl J. Amistaadt is a DMS 2013 Outstanding Contributor Award recipient. He publishes online articles with major focus on pets, wildlife, gardening and fitness. He also covers parenting, juvenile science experiments, cooking and alternative/home remedies. Amistaadt has written book reviews for Work At Home Truth.